Ficus microcarpa, a common ornamental landscape tree (top).  Leaf rolling by the ficus leaf-rolling psyllid, Trioza brevigenae (bottom).  (Photos by Donald R. Hodel, UCCE)

A psyllid, perhaps new to the Western Hemisphere, has been found on Ficus microcarpa (Chinese banyan, Indian laurel fig) in Los Angeles, Orange, San Bernardino, Ventura, San Diego, and Riverside counties.  It causes a distinctive, tight, and typically complete rolling of the leaves.  Ficus microcarpa is one of the most common, useful, and widespread ornamental landscape trees, and has long been a target for numerous pests.

Alessandra Rung, an entomologist and thrips specialist at the California Department of Food and Agriculture, with the help of Daniel Burckhard, a psyllid specialist at the Natural History Museum of Basel, Switzerland identified the psyllid as Trioza brevigenae Mathur.  This psyllid does not have a common name and we refer to it as the ficus leaf-rolling psyllid (FLRP).  FLRP belongs to the family Triozidae in the order Hemiptera.  Triozids are commonly known as tip sheet fleas and along with the members of seven other closely related families, they are also referred to as jumping plant-lice, which is a psynonym for psyllids (Burckhardt and Ouvrard, 2012).

Origin and distribution

FLRP was first detected by coauthor, Linda Ohara on trees in Carson south of Los Angeles in February, 2016 during a routine survey of pests on F. microcarpa (sometimes erroneously referred to as F. nitida or F. retusa)and later observed in several areas including western Los Angeles, Pasadena, Duarte, LongBeach, Lakewood, Claremont, and Universal City (San Fernando Valley) in Los Angeles County; Irvine and Anaheim in Orange County; Thousand Oaks in eastern Ventura County; Oceanside in northern San Diego County; Montclair in western San Bernardino County; and Corona in western Riverside County.  It is likely widespread, perhaps even outside this six-county area.

FLRP is native to India and is not reported from anywhere else in the world (Hodkinson, 1986; Ouvrard, 2013).  It is one of the 22 Trioza spp. in India (Yang and Raman, 2007; Ouvrard, 2013).  It is not clear how it arrived into the US, but the infestation appears to be a recent one as damage was not observed during a previous survey in January, 2016.

Damage

Leaf rolling starts at the tip of the leaf blade and eventually ends as tight rolls (Photos by Donald R. Hodel, UCCE)

FLRP causes a distinctive leaf-rolling of newly developing leaves are tightly rolled into a narrow cylinder, compressed to a diameter of 3-5 mm as they mature.  Leaf rolling is conspicuous on heavily infested trees.  Rolling appears to begin at the distal end or apex of the leaf and progresses adaxially along each margin towards the leaf base.  In some cases, only one margin rolls and stops at the midrib of the leaf.  Damage leaves are brittle, but remain green when only FLRP is present.  Other pests such as mealybugs and the leaf gall wasp, Josephiella microcarpae might also be present in the rolled leaves and cause discoloration or further deformation.  The tight leaf rolling of FLRP is distinct from the loose curling or folding from the Cuban laurel thrips, Gynaikothrips ficorum or the folded-leaf galls caused by the weeping fig thrips, G. uzeli, which also cause reddish scars on the damaged leaves (Dara and Hodel, 2015).  Spiders and other insects may also cause loose leaf rolling that can be easily distinguished from FLRP damage.

Leaf rolling and folding by spiders, which is different from the tight rolling by FLRP (Photo by Donald R. Hodel, UCCE)

Information on the severity or the extent of damage caused by FLRP is not clear, but under severe infestations excessive leaf rolling could affect photosynthesis and thus the plant health.  As seen in some specimens, leaf rolls might also harbor secondary pests.

Biology

Information on the biology of FLRP is lacking in scientific literature.  Adults are 2.6-2.8 mm long with brownish green head and thorax, and protruding red eyes.  Abdomen is green in young adults and turns brown with maturity.  Wings are 3 mm long, transparent with no color pattern, and extend beyond the posterior end of the abdomen.  Females are larger than males.  Adults are typically found outside and adjacent to the rolled leaves.  Nymphs are mobile, 1-2.5 mm long, and oblong with dark greyish tan bodies that turn brownish or brownish green with age.  Advanced nymphal instars have skirts of long, white, waxy filaments at cranial and caudal parts of their bodies.  Wingpads are also visible in latter instars and are extended anteriorly close to the eye level.  Eggs were not found during the observations.

Adult FLRP with protruding reddish eyes, green abdomen, and transparent wings (above).  Mature nymph with white, waxy filaments (below). (Photo by Gevork Arakelian, Los Angeles County)

Emergence of the adult FLRP (above).  Cast skins after the adult emergence (below).  (Photos by Gevork Arakelian, Los Angeles County)

Nymphal instars at different stages of development (above) and a mature nymph and adult FLRP (below).  (Photos by Donald R. Hodel, UCCE)

Adult FLRP with their typical posture of raised abdomens (Photo by Donald R. Hodel, UCCE)

Like many psyllid species, FLRP aligns its body at a 45 degree angle to the leaf surface with a raised abdomen.  It moves the abdomen sideways like a dog wagging its tail.  In a peculiar behavior that FLRP exhibited, adults extended the wings until they are at a right angle to the body and then waved them back and forth.

Being a tropical pest, FLRP was more detectable during warmer (25-30^oC or 76-86^oF or more) and still weather than during cooler, cloudy, and breezy weather conditions.

Management

No information is currently available about the management of FLRP.  Leaf-rolls are likely to protect the immature stages from contact insecticides and possibly from some common natural enemies.  Although wings, lady beetles, and minute pirate bugs were found on the foliage of the infested trees, their role as potential biocontrol agents is not clear.  Initial observations indicated that infestations were higher on trees with younger leaves.  Since FLRP appears to have a tendency to infest newly emerging leaves, careful scouting and removal (and bagging) of the infested leaves can help reduce the spread of infestations.  Depending on the level of infestation and life stages of the pest, contact insecticides for adults and systemic insecticides against immature stages can be considered.  Ficus microcarpa cultivars Green Gem and Variegata, which are resistant to some pests, does not seem to resist FLRP.

Input from a client:

"We successfully controlled a severe outbreak of FLRP on our potted Ficus microcarpa in Chula Vista CA.  I first noticed the rolled leaves in late July. Within 10 days many of the leaves on the ends of all of the branches showed FLRP.  I treated with granular imidacloprid (.55%)+clothianidin per directions and watered in.  This  control worked slowly at first. For 21 days we still saw FLRP in ever reducing numbers.  I retreated every 10 days.  We also used Neem oil on the entire plant in late August, and spot treatment on Sept. 3.  We now have complete control. No curled leaves have been seen since September 4.  This method has of control worked for us." David Pearling, trained horticulture expert

Healthy plant following the treatment. Phto by David Pearling

If you see FLRP infestations contact your local UCCE or Ag Commissioner's office.  You may also contact me at 805-720-1700 or skdara@ucdavis.edu to help me track the distribution of the pest.

This article was based on the original article by Hodel et al. (2016) published in the e-journal, PalmArbor (http://ucanr.edu/sites/HodelPalmsTrees/files/242336.pdf).

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References

Burckhardt, D. and Ouvrard, D.  2012.  A revised classification of the jumping plant-lice (Hemiptera: Psylloidea).  Zootaxa 3509: 1-34. http://www.imok.ufl.edu/hlb/database/pdf/00003080.pdf

Dara, S. K. and Hodel, D. R.  2015.  Weeping fig thrips (Thysanoptera: Phlaeothripidae) in California and a review of its biology and management options.  J. Integ. Pest Mngmt. 6: 2; DOI: 10.1093/jipm/pmv001.

Hodkinson, I. D.  1986.  The psyllids (Homoptera: Psylloidea) of the Oriental Zoogeographical Region: an annotated check-list.  J. Nat. Hstory 20: 299-357.

Hodel, D. R., Arakelian, G., Ohara, L. M., Wilen, C. and Dara, S. K.  2016.  The ficus leaf-rolling psyllid: a new pest of Ficus microcarpa.  PalmArbor 2: 1-9.

Ouvrard, D.  2013.  Psyl'list- The world Psylloidea database.  http://www.hemiptera-databases.com/psyllist

Yang, M.-M. and Raman, A.  2007.  Diversity, richness, and patterns of radiation among gall-inducing psyllids (Hemiptera: Psylloidea) in the orient and Eastern Palearctic.  Oriental Insects 41: 55-65.

Authors

Donald R.  Hodel, Landscape Horticulture Advisor, University of California Cooperative Extension, Los Angeles.

Gevork Arakelian, Entomologist, Los Angeles County Agricultural Commissioner/ Weights & Measures in South Gate, CA.

Linda M.  Ohara, Biological Science Lab Technician, El Camino College in Torrance, CA, a horticulturist, and a former nurserywoman.

Surendra K.  Dara, Strawberry and Vegetable Crops Advisor, University of California Cooperative Extension.

Cheryl Wilen, Area IPM Advisor, University of California Cooperative Extension, San Diego, CA.

Spotted lanternfly (Lycorma delicatula) is an invasive planthopper that was first detected in Pennsylvania in September, 2014 (Dara et al., 2015) and believed to have arrived as eggs attached to stone in a shipment of stone from Asia.  This pest is native to China and has been reported in some other Asian countries.  Since its first occurrence in Berks County in Pennsylvania, it has now spread to 13 counties in the state and was also reported in Delaware and New York in November, 2017 and in Virginia in January, 2018.

Fruit trees (apple, apricot, cherry, peach), ornamental or woody trees (birch, lilac, maple, poplar, tree of heaven), and vines (grape) are among more than 70 species of hosts that are infested by spotted lanternfly.  The tree of heaven (Ailanthus altissima) is a favorite of the spotted lanternfly.  Several invasive pests such as the brown marmorated stink bug and the Asian citrus psyllid first found in late 90s in Pennsylvania and Florida, respectively, have spread to other states and are now found in California.  Considering its current distribution of the spotted lanternfly in Pennsylvania and other states and its potential to spread to other states, this article provides an update on recent efforts to monitor and control this pest.

Biology and damage

Eggs are deposited in masses and covered by a waxy substance.  There are four nymphal instars.  Female lanternflies are larger than males.  Nymphs and adults feed on the phloem and excrete large volumes of liquid.  Severe feeding damage results in oozing wounds on the trunk, and wilting and death of affected branches.

Egg masses of the spotted lanternfly. Photo by Lawrence Barringer, Pennsylvania Department of Agriculture.

Fourth instar nymph of the spotted lanternfly. Photo by Lawrence Barringer, Pennsylvania Department of Agriculture.

Adult spotted lanternfly infestations.  Photo by Lawrence Barringer, Pennsylvania Department of Agriculture.

White mold developing on the excretions of the spotted lanternfly. Photo by Lawrence Barringer, Pennsylvania Department of Agriculture.

Monitoring and controlling

Preventing the movement: To prevent the spread of the spotted lanternfly, carefully inspect potential sources such as woody plant debris, yard waste, plants, or other objects.  Destroy or disinfest the sources as appropriate to prevent the spread of the pest.

Removal of the host: Removing tree of heaven, a favorite host of the spotted lanternfly and an invasive species of tree, can reduce the risk of pest infestation and spread.  Reducing the plant stand to 15% is considered a primary strategy for preventing the spread of spotted lanternfly. The tree should be removed with its entire root system when possible.  If the tree was cut, its stump should be treated with herbicides to prevent regrowth.  Care should be taken while removing the tree of heaven since the toxic plant sap can cause skin irritation, headaches, nausea, and in some cases cardiac problems.  Sumac and black walnut trees also look similar to the tree of heaven, but when bruised, the leaves of the latter give out a rancid peanut butter odor.

Sticky bands: The Pennsylvania Department of Agriculture placed 13 counties under quarantine and is currently providing sticky bands for volunteers participating in the monitoring program to place on trees.  Sticky bands are placed around the tree trunk about 4' from the ground to trap the nymphs and adults that are moving around.  While younger nymphs can be captured on less sticky bands, stickier bands are necessary to capture older nymphs and adult hoppers.  Those not participating in the volunteer program can purchase sticky bands or sticky substances from commercial vendors or make their own by wrapping a tape around the trunk and applying petroleum jelly or other materials on the tape.  This strategy helps to detect and trap the pest infestations.  More than 1.7 million spotted lanternflies were reported to be trapped in 2017 in Pennsylvania using sticky bands.

Spotted lanternfly nymphs and some adults trapped on a sticky band.  Photo by Lawrence Barringer, Pennsylvania Department of Agriculture.

Pesticides: Contact insecticides, bifenthrin and carbaryl and systemic insecticides, dinotefuran and imidacloprid appear to be effective in controlling the spotted lanternfly based on the studies conducted in Pennsylvania.  Neem oil and insecticidal soap also provide some control.  However, pesticide applications appear to be a short-term solution as they cannot prevent reinfestation.

Biocontrol agents:It is thought that toxic metabolites in the body of the spotted lanternfly and its brightly colored hindwings tend to deter general predators from feeding on the pest.  However, the predatory wheel bug, Arilus cristatus (Hemiptera: Reduvidae) and stink bug, Apoecilus cynicus were found feeding on adult spotted lanternfles in Pennsylvania (Barringer and Smyers, 2016). Some egg parasitoids were also reported to be attacking the spotted lanternfly in China (Choi et al., 2014) and South Korea (Kim et al., 2011).  Liu and Mottern (2017) found Ooencyrtus kuvanae, an egg parasitoid imported for controlling the gypsy moth (Lymantria dispar), attacking the egg masses of the spotted lanternfly in Pennsylvania in 2016.  These native predators and introduced parasitoids could be potential biocontrol options for the spotted lanterfly. 

Microbial control agents: Entomopathogenic fungi Beauveria bassiana, Isaria fumosorosea, and Metarhizium brunneum may also play a role alone or in combination with azadirachtin for controlling spotted lanternfly and researchers should explore microbial control.

Refer to the earlier article on the pest biology and damage at http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=15861 

Spotted lanternfly in Entomology Today: https://entomologytoday.org/2015/12/17/be-prepared-for-spotted-lanternfly/  

References

Barringer, L. E. and E. Smyers.  2016.  Predation of the spotted lanternfly, Lycorma delicatula (White) (Hemiptera: Fulgoridae) by two native hemiptera.  Entomol. News 126: 71-73.  https://doi.org/10.3157/021.126.0109

Choi, M. Y., Z.Q. Yang, X. Y. Wang, Y. L. Tang, and Z. R. Hou. 2014. Parasitism rate of egg parasitoid Anastatus orientalis (Hymenoptera: Eupelmidae) on Lycorma delicatula (Hemiptera: Fulgoridae) in China. Korean J. Appl. Entomol. 53: 135–139.

Dara, S. K., L. Barringer, and S. P. Arthurs.  2015.  Lycorma delicatula (Hemiptera: Fulgoridae): A new invasive pest in the United States.  J. Integ. Pest Mngmt. 6(1): 20.  https://doi.org/10.1093/jipm/pmv021

Kim, I. K., S. H. Koh, J. S. Lee, W. I. Choi, and S. C. Shin. 2011b. Discovery of an egg parasitoid of Lycorma delicatula (Hemiptera: Fulgoridae) an invasive species in South Korea. J. Asia Pac. Entomol. 14: 213–215.

Liu H. and J. Mottern.  2017.  An old remedy for a new problem?  Identification of Ooencyrtus kuvanae (Hymenoptera: Encyrtidae), and egg parasitoid of Lycorma delicatula (Hemiptera: Fulgoridae) in North America.  J. Ins. Sci. 17: 1-6. https://doi.org/10.1093/jisesa/iew114

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